1. Field of the Invention
This invention relates generally to reproduction apparatus operable in both copier and printer modes such as, for example, electrophotographic copier/printers.
2. Background Art
In U.S. Pat. No. 5,105,283, description is provided of an electrophotographic reproduction apparatus that is operable in both copier and printer modes. As used herein, the term "copier" is meant to refer to apparatus arranged for reading the image information on an original document sheet and for reproducing such image information on a receiver or copy sheet, which is a "hard copy." The term "printer" is meant to refer to apparatus arranged for receiving image information in other than hard copy form, referred to as electronic form, and for reproducing such image information on a receiver sheet. The term "original" is meant to refer to image information to be reproduced, whether such image information is in hard copy, electronic or other form. The term "reproduction apparatus" is meant to refer to copiers and/or printers. The term "print job" is used in its conventional sense and implies operation of the apparatus in a printer mode to produce one or more hard copy sets of data in accordance with predetermined parameters requested for producing said copy sets. The data may represent one or more pages of data. The term "copy job" is used in its conventional sense and implies operation of the apparatus in a copier mode to produce one or more hard copy sets from a job requiring copying of an original document having one or more hard copy pages in accordance with predetermined parameters requested for producing said copy sets.
A typical job represents a request to either print or copy a page or a sequence of pages. Where it represents a sequence of pages, the pages will be collated as a group or output finished such as by stapling.
In known copier/printer reproduction apparatus, a problem is associated with management of the copier and printer functions since only one marking engine is available for reproducing the information on the copy sheets. More specifically, a job image buffer memory is available as an interface to a writer for storing in rasterized form the information to be printed or copied. The buffer may, for example, have a capacity for storing image data for printing or copying about 50 pages. While this is more than enough necessary for most reproduction job, at times there are jobs that require about this amount of memory or more. It would also be desirable to allow for interruption of print jobs in progress to allow access to the apparatus for reproduction of a copy job. In order to provide for such interrupts, an apparatus might provide for one print job to be sent to the job image buffer at a time. Upon an interrupt, an original document may be scanned in and copied. However, operation of the printer/copier in this manner as will be shown, limits the productivity thereof.
It is therefore an objective of the invention to provide a copier/printer apparatus with improved productivity.